1. Field of the Invention
This invention relates to a junction box and a connector containing a connecting terminal for electrically connecting a fuse or the like to a wiring circuit. More particularly, the present invention relates to a junction box and a connector that are lightweight and low-profiled so as to promote the trend of down-sizing and allow to freely shift the point of connection with external wiring circuit, while showing a high heat emitting effect.
2. Description of the Related Art
In general, to branch a wiring of a car or the like, a junction box (J/B) has been used for purposes of space saving and cost reduction. FIG. 23 is a plan view of the junction box, FIG. 24 is a plan view of a bus bar contained in the junction box, FIG. 25 is a sectional view of a part VII of FIG. 23, and FIG. 26 is a sectional view of a part VIII of FIG. 23.
This type of a junction box 101 is constituted of a lower cover 102, a bus bar 103 attached to the lower cover 102, and an upper cover 105 which seals the lower cover and bus bar and to which a connector, fuse, and the like are attached. In the junction box 101, as shown in FIG. 24, the bus bar 103 formed, for example, of a pressed/punched metal plate of copper alloy, aluminum alloy, or the like is used to branch the wiring. Moreover, the junction box 101 also includes a function, for example, of a fuse box, when a fuse 108 is incorporated halfway in the wiring circuit constituted by the bus bar 103.
A connector 107 shown in FIG. 25 is a connector connected to the wiring circuit constituted of the bus bar 103. A connector 105a can be connected to the connector 107, when a connecting terminal portion 103a formed by bending a tip end of the bus bar 103 upwards by 90° is passed upwards through an upper cover 105 via a through hole 105b formed in the cover. Moreover, for a fuse attachment portion 105c to which a fuse 108 is attached as shown in FIG. 26, a connecting terminal portion 103d is formed by bending the tip end of the bus bar 103 with a slit 103b formed therein upwards by 90°, and is passed upwards through the upper cover 105 through a through hole 105d formed in-the cover. Thereby, the connecting terminal portion can directly be connected to a leg 108a for connecting the fuse 108, or can be connected using a so-called female to female (F—F) terminal.
Moreover, as shown in FIG. 27, the bus bars 103 and insulation plates (IP) 109 having functions of supporting and insulating the bus bars 103 are alternately superimposed to form a wiring circuit (multilayered wiring circuit) 110 which has a multilayered structure. A junction box 112 structured to contain the multilayered wiring circuit 110 in a housing for entirely protecting the outside of the circuit as shown in FIG. 28 is frequently used.
However, in the above-described junction box 101, the bus bar 103 is manufactured by punching the metal plate with a die and the wiring circuit is formed. Therefore, when the bus bars 103 having various shapes are manufactured, different dies are required, and much cost is taken. Moreover, the bus bar 103 is formed of a thick metal, a weight of the junction-box 101 therefore increases, and there is a problem that it is difficult to thin the junction box 101. Furthermore, in the junction box 112, the number of layers of the multilayered wiring circuit 110 needs to be minimized in order to prevent the weight and cost of the entire junction box from increasing. Additionally, the multilayered wiring circuit 110 having a small number of layers is used in accordance with a connection mode. For this, a circuit is drawn so as to avoid a wiring circuit of another layer and through holes 111 through which the connecting terminal portions 103a, 103d are passed, and a long circuit needs to be formed. This causes a problem that it is very difficult to lighten and thin the junction box 112.
Furthermore, since each of these junction boxes 101, 112 has a part thereof that is integral with it and on which a connector or a fuse is mounted, it inevitably shows certain dimensions and hence is subjected to certain restrictions particularly in terms of the position in a car where it is mounted. Additionally, since it has a structure in which the bus bar 103 is contained in a predetermined cabinet to make it show a rather poor heat emitting performance. Therefore, it is difficult to downsize the junction box and make is lightweight and lowly profiled particularly when it is to be used with a circuit adapted to allow a large electric current to flow. Furthermore, since the part on which a connector or a fuse is mounted is integrally formed with it, the operation of connecting the connector of an external wiring circuit to it will have to be carried out only poorly efficiently to baffle the efforts for improving the efficiency when the part, on which a fuse is mounted, is arranged on the front surface of the instrument panel of a car that is provided with a conventional junction box 101 or 112 for the purpose of improving the servicing efficiency.